Putter Fitting Method for Optimum Weight

ABSTRACT

A method for fitting a putter club to an individual golfer includes steps of obtaining performance data for the golfer using a plurality of putter configurations with a range of putter weights and mass-moment of inertia. This novel system uses putter head weight variation over a very wide range exceeding the putter head weights generally otherwise available. The system further uses very small increments of weight change over the very wide range to determine the optimal weight for the golfer. A particular putter weight is selected based on the optimal performance data collected for the golfer.

BACKGROUND OF THE INVENTION

Putter fitting has historically been based first on appearance, feel and sound; and secondly on putter length and lie angle. A significant number of systems have been developed and marketed to facilitate fitting for lie angle and length. Some fitting methods include an analysis of stroke shape; including anecdotal recommendations for more toe hang for strokes with dramatic arc and face balanced putters for strokes with little or no arc. Putter weight fitting has historically been very limited and based only on feel or swingweight, and not on performance criteria.

The fact that very few putters offer any weight adjustment at all has naturally limited the offering of weight fitting by their manufacturers. Putters that have weight adjustment capability offer weight adjustment over only a very limited range; most commonly about 30 grams. This limited weight adjustability is typically used to maintain swingweight.

The industry standard for men's swingweight is typically designated with the labels D0 to D2. Women's is C6 to C8. If a putter is shortened from 35 inches to 34 inches the swingweight will decrease by about 6 swingweight points. If it is further shortened to 33 inches the swingweight will be reduced by an additional 6 points; a total of about 12 swingweight points. To maintain putter swingweight, some putter manufacturers offer heads with weights varying by about 30 grams, that is, 335 grams, 350 grams and 365 grams. Most putters are not weight adjustable at all; except by adding lead tape or other weighting material. Junior golfers, with even shorter putters, are particularly ill-served by the lack of weight adjustability in putters. With their very short putters, these juniors are forced to put with extremely light, low swingweight putters.

Swingweight fitting assumes that a putter should be about the same swingweight as the rest of a golfer's set of clubs. This anecdotal assumption assumes that the putter is swung in the same way as the other clubs; it is not. 40 years ago, putters were swung, with a distinct wrist break. On today's much faster greens, putters are no longer swung in the same way. The modern putting stroke limits wrist break dramatically. The modern putter stroke is a pendulum stroke based on maintaining wrist and arm relationships.

Putters have been gradually becoming heavier over the last 50 years. Putter head weight 50 years ago was very light, around 300 grams. The original Scottsdale Ping Anser (Trademark-Karsten Manufacturing Corp.) style putter, introduced in about 1966, weighed only 310 grams. Today's “Anser” style putters have increased in weight to about 345 grams. Putters are available today with weights of from 330 grams to about 400 grams. Very few putters have a weight over 400 grams.

The choice of light versus heavier putter is generally understood to be a matter of user feel or tempo; and an aesthetic choice for the individual golfer. With the advent of putting launch monitors that provide detailed data regarding both the putter club and the ball, it is possible to develop performance data for putters with varying specific characteristics.

Because so few putters have any weight adjustment at all, methods for putter fitting have been focused on comparing other putter characteristics; or more commonly one putter model to another. Incremental variation of a putter variable like loft, lie and length has been incorporated in some fitting systems; but incremental variation of weight has not been explored fully.

Existing putter fitting protocols have focused on launch angle, spin rates and aiming improvements. Existing club fitting (irons and woods) has focused similarly on launch angle and spin rates, with special attention on shaft variations. Numerous methods and systems for testing irons and woods exist. Far fewer putter fitting methods and systems exist and none of them have focused on incremental wide range weight optimization.

The putter industry has widely claimed that increased mass moment of inertia (MOI) means increased stability; but very little scientific evidence has been offered. Putter stability is widely understood to be very important in putter performance. On an off-center hit, a high MOI putter is more stable than a low MOI putter; meaning that the putter will twist less (about a vertical axis) at impact and the impact will therefore be more efficient. Twist at impact causes the ball to be sent off line. Twist at impact also reduces the resulting ball speed, so a putt will not travel as far. Twist at impact therefore results in both poor directional control performance and poor distance control performance. A higher MOI putter will be a more forgiving putter.

While the potential general improvement of putting accuracy with increased MOI is understood, there has been no understanding of whether and how changes in MOI affects individual users and no understanding of fitting individual users to maximize putting performance. What is needed to further improve putter accuracy is a way to tailor a putter weight over a very wide range to individuals' characteristics.

SUMMARY OF THE INVENTION

The invention is based on the novel recognition that a human user can have an optimum putter weight and associated moment of inertia (MOI) that optimizes user putter accuracy and performance independent of user aiming. By changing a user's putter weight over a very wide range and hence increased MOI at any given weight and testing user accuracy and performance an optimum putter weight characteristic can be determined.

The present invention employs multiple golf putter configurations with associated putter head weight adjustment over a sufficiently wide range to discern changes in typical individual user's performance and thereby determine an optimum putter weight and moment of inertia (MOI). This includes configurations from very low weights (less than 340 grams) up to very high weights (in excess of 600 grams).

In a preferred embodiment of the inventive method, a putter capable of changeable weight and MOI is provided, together with means of detecting and measuring at least one performance parameter. The putter should have an adjustable weight in the range of 300 to 600 grams. A user is directed to complete multiple putts, each putt consisting of the user striking a ball with the putter in typical fashion, for each of specified multiple weights. For each weight, the user completes multiple putts and the specified performance parameter is measured and recorded. An optimum weight and MOI for the user is identified from the values of the performance parameter. Any of a number of different parameters may be used to define performance, including for example: putter face angle variation range; putter speed variation range; ball launch angle. In a preferred configuration of the inventive method, putter face angle is measured and a minimum value of the face angle variation range is used as an indicator of an optimum putter weight and configuration. In alternative configurations of the method, multiple putters, each with a unique weight and MOI, is used to provide the multiple weight and MOI values.

The invention includes a putter having weight and MOI characteristics adjustable through a range of values including optimum values for a majority of human users. The adjustment includes weight increments no greater than 12 grams to discern typical putter performance parameters.

DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a test station for carrying out a first step.

FIGS. 2A and 2B illustrate further steps of the inventive method.

FIGS. 3A, 3B and 3C provide test results according to the inventive method.

FIG. 4 is a perspective view of a putter configuration enabling the inventive methods.

DETAILS OF EMBODIMENTS OF THE INVENTION

The inventive method enables the identification of a user associated optimum configuration of weight in a putter with variable weight configurations. In a putter of any design and range of weights, the inventive method can distinguish which weight or weight configuration will result in the lowest face angle variation range; and/or putter speed variation range; best launch angle; etc. which will result in improved putting performance with a specified user. It is important to note it is believed that the optimum (particularly, lowest face angle variation range) configuration of a putter is dependent in part on the user and the user's kinesiological and biomechanical interaction with the putter during use. For example, players with a slower tempo will likely perform best with a heavier putter and players with a faster tempo will likely perform best with a lighter putter. As such, when the act of putting is discussed herein, it should be understood that a specified associated user is engaged with the putter. The results of the putting performance, and therefore the results of the inventive method are associated with a combination of a particular putter and a specified user.

While the inventive method enables determining an optimum weight configuration among any various different putter weight configurations, it has been determined that for the majority of human users there is a range of putter weights and mass-moment of inertia (MOI) within which an optimum for the user can be determined.

In accordance with the present invention, an optimum putter weight and moment of inertia (MOI) for an individual golf player user is established by user performance putting test results in which putter weight is incrementally changed over a very wide range to alter both weight and MOI. At least one of a variety of possible putter performance parameters are detected and recorded during testing. Variations in the performance parameters indicate optimum weight and MOI. While adding MOI theoretically (actually) increases stability, the present invention determines the optimum weight and and associated MOI for any individual. Adding weight above this determined optimum weight will increase MOI and stability but will not improve performance.

FIG. 1 depicts a test station for carrying out a first step in a preferred embodiment of the inventive method. The figure is a plan view of a horizontal putting surface 10. The surface 10 may be a conventional grass putting “green” or a synthetic facsimile thereof. The surface 10 should include a target 12 which may be a conventional putting hole or a graphical indicia or other element that may serve the same purpose of providing a visual target reference point. The putter 100 to be used in the test is located in conventional position and attitude on the surface 10. Herein, reference to the putter 100 means the putter head and characteristics of the putter head alone. That is, the weight and MOI is of the putter head alone without consideration of the characteristics of other portions of the putter such as the shaft. The putter head being the portion of the putter that is located at the distal end of the putter and is used to strike a ball.

Generally, the putter 100 should be held by the subject human user (not illustrated) and the user instructed to, at all times, attempt to use the putter in a fashion replicating the user's action in the course of golf activities. For example, the user should “address” the ball in his/her normal fashion; taking his/her normal putting stance and posture, ready to initiate a putting stroke. The actions of the user, including the actually striking of the ball, is termed here a “putt”. While the user is supporting the putter 100, an alignment device is used to align the putter 100 with the target. In the example shown, the alignment device 20 is provided by a laser light emitting device placed against the face of the putter 100 such that a light beam 22 is emitted along parallel to and coicident with the line-of-aim 112 of the putter 100. Generally, the putter line-of-aim is a line passing through the intended strike point of the putter 100 and perpendicular to the putter 100 at that point. Using this alignment device 20, the putter 100 is oriented such that its line-of-aim 112 passes through the center of the target 12 (assuming an absolutely level putting surface). The alignment device 20 may then be removed and a conventional golf ball placed in its position (not shown).

In the following steps, the user should attempt to aim the putter 100 on the line-of-aim 22 established with the laser; and thereafter initiate and complete a normal putting stroke, striking the ball and sending it along the line-of-aim 22.

FIG. 2A is a plan view of the putting surface 10 and putter 100. In a first step, the putter 100 has a first configuration with a determined or measured weight and MOI. From this maintained position and attitude, the user uses the putter 100 to strike a multiple of conventional balls in conventional fashion on the line-of-aim 22, attempting to return the putter face at impact as close as possible to the line-of-aim 22. Possible example face angle lines 36 are shown for six test putts. The face angle lines 36 are lines perpendicular to the putter face at impact. The initial face angle variation range 50 is the range or variation from the furthest left face angle to the furthest right face angle. Reducing the face angle variation range 50 will result in more putts being closer to the line-of-aim 22; and therefore improve putting performance.

As illustrated, the face angle lines 36 vary from putt to subsequent putt. The deviation of face angle line 36 of each putt from the intended line-of-aim is at least in part due to failure to return the putter 100 to the line-of-am. The face angle variation range 50 can calculated based on the face angle variation of the individual putts in a test.

During the inventive method, a multiple of balls are struck by the user in the same fashion and at least one putter performance parameter is determined and recorded for each event. In this step, the putter configuration, weight and MOI, is unchanged. Because human performance in putting is found to be erratic and variable, a single putt is unlikely to generate data that is representative of the putter characteristics of interest. As a result multiple balls must be struck, separately, in sequence, and data obtained from each, to generate meaningful data. Preferably, at least six balls (putts) are believed to be sufficient to generate the required information. Tests with more than 6 balls are more accurate; more than 20 balls is believed to be unnecessary.

Other putter performance parameters may be defined by motions and positions of the putter during the putting action, such as at the moment the putter strikes the ball or before and after. A variety of useful performance parameters may be determined by optical means using systems such as the “Quintic Ball Roll” (trademark of Quintic Consultancy Ltd. of UK) system. These systems use high speed cameras to photograph create images of the putters and ball during and after putting actions. From this information and data the performance parameters may be detected and measured. In FIG. 2A, a launch monitor device 40 is positioned to measure movements performance parameters during testing. The placement and configuration of the launch monitor 40 may depend on the nature of the system used and the illustrated configuration should not be considered defining or limiting. While an optical system is used in the embodiments illustrated, other methods and devices for obtaining the same data or otherwise carrying out the function specified.

Using the inventive methods and devices various different putter performance parameters that may be likewise measured or determined including: putter head face angle variation range at ball impact, putter speed and variation range at impact, ball speed variation at impact, zero skid point and variation, ball launch angle and variation. Each of these may evidence movement or other conditions of the putter during a putting stroke that may be affected by stability of the putter that may be altered by changes in weight and MOI.

In a subsequent step in the present method, the weight and therefore MOI of the putter head is changed to form a second putter configuration. Preferably, in the first step above, a relatively low weight and MOI is used. Most preferably, the initial putter configuration for the first step is a putter that is previously used by the user, or is a putter configuration having closely matching properties. It can be presumed that such an initial putter configuration will have a weight and MOI below an optimum value, in which case subsequent testing steps may be carried out with subsequent putters, or putter configurations, having increased weight and, or, MOI. As in the first step, multiple balls are struck by the user using the putter having the second weight and MOI configuration, and respective movement performance parameters determined and measured. This data is recorded.

FIG. 2B illustrates example results of a second step test with a changed configuration from of FIG. 2A. Improved stability has resulted in an improved face angle variation range 51. The improved face angle variation range 51 is reduced from the previous 50 (FIG. 2A)

The step of changing the putter configuration weight and MOI (or introducing a different configuration) and striking multiple balls to obtain putter performance parameter data is repeated until an uncomfortably high putter weight is reached. This maximum may be determined by ad hoc analysis of putter performance parameters to detect an optimum putter configuration, or a maximum is determined by the feel of the player. The test is carried out and the optimum determined from review of all data.

A maximum possible putter weight of at least about 500 grams is suggested. However, it is possible that particular combinations of users and putters may require greater weight and MOI to reach an optimum configuration. In any test sequence, if a optimum configuration is not found, testing may be continued with greater weight and MOI values until a optimum is determined.

After a series of test steps, gathering putter performance parameter data for a range of putter weight configurations, the optimum weight configuration is determined by the performance parameter data. The indicator of the optimum weight is a minimum value for the selected putter performance parameter. For example, an optimum configuration based on putter face angle is the configuration having a minimum face angle variation range. The range being the angle (or similar dimension) encompassing all putts respecting a putter weight and MOI configuration.

FIGS. 3A, 3B and 3C provide data from three separate optimizations for three distinct users according to the present method. Each figure provides a graph of putter face angle variation in degrees (about a vertical axis) and putter weight in grams with putter MOI in gram·cm². Each data point represents the face angle variation range resulting from a series of putts with a common putter configuration having the indicated weight/MOI characteristics. The face angle variation range was measured in all cases using an optical system as discussed above. In each figure, the data point at the furthest left is the result for the user with a conventional putter that the user had historically used. The remaining data points represent the results of incrementally increasing weight and MOI configurations of a common test putter. The data point at the lowest face angle variation range (respectively: 0.50, 0.75, 1.25) indicate an optimum putter weight configuration for the respective user. Typically additional weight added above the user's optimum results in no further improvement in face angle variation.

An inventive putter is preferably provided with features to carry out the required optimization functions. FIG. 4 is a perspective view of an inventive putter head 110, shown on a shaft (cut-away for clarity). From the back of the head 110 extend two horizontal stacks of adjustment weights 40. The weights 40 are individually removeable and replaceable with alternative weights having different weight such as to enable altering the weight and MOI of the total putter. Proper selection or design of the weight individually and as a set will allow the desired optimization process. In particular, total putter weight should be changed by increments of no more than 12 (twelve) grams to enable discerning the weight and MOI at the performance optimum. That is, if the smallest weight adjustment is more than 12 grams, incremental tests may fall on either side of the optimum and therefore not demonstrate optimum performance and therefore such is not suggested. These values presume that the weights are relatively located at a maximized separation distance DD (between centers) creating a maximized radius of gyration for the putter. Total weight may be incrementally changed by use of weight sets or combinations having individual values greater than or less than 12 grams as well by weights of 12 grams. The putter configuration shown uses weights having a circular (cylindrical) form. Other alternative shapes may be used to equal effect.

FIG. 4 also illustrates a performance parameter that may used to determine optimum putter configuration in the manner discussed above. Putter twist TT is defined as a rotation of the putter head 110 about a vertical axis that initiates on striking the ball and is typically a result of a off-center strike. The degree of twist will result in a face angle deviation dimension FA of the putter from the initial line of action 112.

In a preferred embodiment of the inventive method, a putter according to the above specifications and requirements is provided, together with means of detecting and measuring at least one putter performance parameter. The putter should have an adjustable weight range of 300 to 600 grams and include incremental weights of no more than 12 grams each. The inventive steps are carried out as described above for specified multiple weights and MOIs within the weight and MOI range. For each weight and MOI, the user completes multiple putts and the specified performance parameter is measured and recorded. An optimum weight and MOI for the user is identified from the minimum value of the putter performance parameter.

The above description is that of current embodiments of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims. This disclosure is presented for illustrative purposes and should not be interpreted as an exhaustive description of all embodiments of the invention or to limit the scope of the claims to the specific elements illustrated or described in connection with these embodiments. For example, and without limitation, any individual element(s) of the described invention may be replaced by alternative elements that provide substantially similar functionality or otherwise provide adequate operation. This includes, for example, presently known alternative elements, such as those that might be currently known to one skilled in the art, and alternative elements that may be developed in the future, such as those that one skilled in the art might, upon development, recognize as an alternative. Further, the disclosed embodiments include a plurality of features that are described in concert and that might cooperatively provide a collection of benefits. The present invention is not limited to only those embodiments that include all of these features or that provide all of the stated benefits, except to the extent otherwise expressly set forth in the issued claims. Any reference to elements in the singular, for example, using the articles “a,” “an,” “the” or “said,” is not to be construed as limiting the element to the singular. 

1. A method of fitting a golf putter to a user, comprising: providing multiple putters with a common configuration and each putter having a unique weight and mass-moment of inertia; completing a putting test, for each putter, comprising: allowing a user to strike a golf ball with a putter to induce the ball to roll toward a target; detecting at least one putter performance parameter while or after the putter strikes the ball; and recording at least one performance parameter; repeating the putting test a multiple of times for each putter; and determining an optimum putter weight and mass-moment of inertia from the associated performance parameters.
 2. A method of fitting a golf putter to a user, comprising: providing a putter having a first configuration having a unique weight and mass-moment of inertia; completing a putting test comprising: allowing a user to strike multiple golf balls with a putter to induce each ball to roll toward a target; detecting, for each ball, at least one putter performance parameter while or after the putter strikes the ball; and recording at least one performance parameter for each ball; changing the weight and mass-moment of inertia of the putter to form multiple subsequent unique putter configurations; repeating the putting test for each subsequent putter configuration; and determining an optimum putter weight and mass-moment of inertia from the associated performance parameters.
 3. A method, according to claim 2, and wherein: the performance parameter is a measure of putter angular rotation.
 4. A method, according to claim 2, and wherein: the performance parameter is a measure of ball movement.
 5. A method, according to claim 2, and wherein: the step of detecting at least one putter performance parameter comprises recording optical images of the putter while or after the putter strikes the ball.
 6. A method, according to claim 2, and wherein: the putter weight is changed by an incremental weight equal to no more than 12 grams.
 7. A method, according to claim 2, and wherein: the putter configurations each have a weight in the range of 300 to 600 grams.
 8. A method, according to claim 7, and wherein: the putter configurations comprise a second configuration having a weight of about 300 grams and a third configuration having a weight of at least 600 grams. 